The post-translational modification of proteins by ubiquitin-like molecules (ubls) is an important regulatory process within cells, playing key roles in controlling many biological processes including cell division, cell signaling and the immune response. Ubls are small proteins that are covalently attached to a lysine on a target protein via an isopeptide linkage with a C-terminal glycine of the ubl. The ubiquitin-like molecule alters the molecular surface of the target protein and can affect such properties as protein-protein interactions, enzymatic activity, stability and cellular localization of the target.
Ubiquitin and other ubls are activated by a specific E1 enzyme which catalyzes the formation of an acyl-adenylate intermediate with the C-terminal glycine of the ubl. The activated ubl molecule is then transferred to the catalytic cysteine residue within the E1 enzyme through formation of a thioester bond intermediate. The E1-ubl intermediate and an E2 associate, resulting in a thioester exchange wherein the ubl is transferred to the active site cysteine of the E2. The ubl is then conjugated to the target protein, either directly or in conjunction with an E3 ligase, through isopeptide bond formation with the amino group of a lysine side chain in the target protein.
Targeting E1 activating enzymes provides a unique opportunity to interfere with a variety of biochemical pathways important for maintaining the integrity of cell division and cell signaling. E1 activating enzymes function at the first step of ubl conjugation pathways; thus, inhibition of an E1 activating enzyme will specifically modulate the downstream biological consequences of the ubl modification. As such, inhibition of these activating enzymes, and the resultant inhibition of downstream effects of ubl-conjugation, represents a method of interfering with the integrity of cell division, cell signaling, and several aspects of cellular physiology which are important for disease mechanisms. Thus, E1 enzymes such as UAE, NAE, and SAE, as regulators of diverse cellular functions, are potentially important therapeutic targets for the identification of novel approaches to treatment of diseases and disorders.
Langston S. et al., Intl. App. Pub. No. WO 07/092213 and Langston S. et al., U.S. App. Pub. No. 2007/0191293, which are hereby incorporated by reference in their entirety, disclose compounds which are effective inhibitors of E1 activating enzymes, particularly NAE. The compounds are useful for inhibiting E1 activity in vitro and in vivo and are useful for the treatment of disorders of cell proliferation, particularly cancer, and other disorders associated with E1 activity. One class of compounds described in Langston et al. are 4-substituted ((1S,2S,4R)-2-hydroxy-4-{7H-pyrrolo[2,3-d]pyrimidin-7-yl}cyclopentyl)methyl sulfamates. Armitage I. et al., U.S. App. Pub. No. 2009/0036678, which is hereby incorporated by reference in its entirety, discloses methods for the preparation of ((1S,2S,4R)-2-hydroxy-4-{7H-pyrrolo[2,3-d]pyrimidin-7-yl}cyclopentyl)methyl sulfamates, including ((1S,2S,4R)-4-{4-[(1S)-2,3-dihydro-1H-inden-1-ylamino]-7H-pyrrolo[2,3-d]pyrimidin-7-yl}-2-hydroxycyclopentyl)methyl sulfamate. This compound has been reported to be a selective NAE inhibitor. See, e.g., Soucy, T. A., et al., Nature, 2009, 458, 732-737 (which refers to the compound as MLN4924).
These applications additionally disclose pharmaceutical compositions containing these compounds, and methods for the treatment or therapy of diseases, disorders, or conditions associated with E1 activating enzymes, particularly NAE, including proliferative diseases such as cancer.
((1S,2S,4R)-4-{4-[(1S)-2,3-dihydro-1H-inden-1-ylamino]-7H-pyrrolo[2,3-d]pyrimidin-7-yl}-2-hydroxycyclopentyl)methyl sulfamate (II) is described in Intl. App. Pub. No. WO 07/092213, U.S. App. Pub. No. 2007/0191293, and U.S. App. Pub. No. 2009/0036678. The potassium salt of ((1S,2S,4R)-4-{4-[(1S)-2,3-dihydro-1H-inden-1-ylamino]-7H-pyrrolo[2,3-d]pyrimidin-7-yl}-2-hydroxycyclopentyl)methyl sulfamate is disclosed in Intl. App. Pub. No. WO 07/092213 and U.S. App. Pub. No. 2007/0191293.

The large-scale manufacturing of a pharmaceutical composition poses many challenges to the chemist and chemical engineer. While many of these challenges relate to the handling of large quantities of reagents and control of large-scale reactions, the handling of the final product poses special challenges linked to the nature of the final active product itself. Not only should the product be prepared in high yield, be stable, and be capable of ready isolation, the product should possess properties that are suitable for the types of pharmaceutical preparations in which they are likely to be ultimately used. The stability of the active ingredient of the pharmaceutical preparation must be considered during each step of the manufacturing process, including the synthesis, isolation, bulk storage, pharmaceutical formulation and long-term storage. Each of these steps may be impacted by various environmental conditions of temperature and humidity.
The pharmaceutically active substance used to prepare the pharmaceutical compositions should be as pure as possible and its stability on long-term storage should be guaranteed under various environmental conditions. These properties are useful to prevent the appearance of unintended degradation products in pharmaceutical compositions, which degradation products may be potentially toxic or result simply in reducing the potency of the composition.
A primary concern for the large-scale manufacture of pharmaceutical compounds is that the active substance should have a stable crystalline morphology to ensure consistent processing parameters and pharmaceutical quality. If an unstable crystalline form is used, crystal morphology may change during manufacture and/or storage resulting in quality control problems and formulation irregularities. Such a change may affect the reproducibility of the manufacturing process and thus lead to final formulations which do not meet the high quality and stringent requirements imposed on formulations of pharmaceutical compositions. In this regard, it should be generally borne in mind that any change to the solid state of a pharmaceutical composition which can improve its physical and chemical stability gives a significant advantage over less stable forms of the same drug.
When a compound crystallizes from a solution or slurry, it may crystallize with different spatial lattice arrangements, a property referred to as “polymorphism.” Each of the crystal forms is a “polymorph.” While polymorphs of a given substance have the same chemical composition, they may differ from each other with respect to one or more physical properties, such as solubility, dissociation, true density, dissolution, melting point, crystal shape, compaction behavior, flow properties, and/or solid state stability.
As described generally above, the polymorphic behavior of drugs can be of great importance in pharmacy and pharmacology. The differences in physical properties exhibited by polymorphs affect practical parameters such as storage stability, compressibility and density (important in formulation and product manufacturing), and dissolution rates (an important factor in determining bio-availability). Differences in stability can result from changes in chemical reactivity (e.g., differential oxidation, such that a dosage form discolors more rapidly when it is one polymorph than when it is another polymorph) or mechanical changes (e.g., tablets crumble on storage as a kinetically favored polymorph converts to a thermodynamically more stable polymorph) or both (e.g., tablets of one polymorph are more susceptible to breakdown at high humidity). In addition, the physical properties of the crystal may be important in processing: for example, one polymorph might be more likely to form solvates that cause the solid form to aggregate and increase the difficulty of solid handling, or might be difficult to filter and wash free of impurities (i.e., particle shape and size distribution might be different between one polymorph relative to other).
While drug formulations having improved chemical and physical properties are desired, there is no predictable means for preparing new drug forms (e.g., polymorphs) of existing molecules for such formulations. These new forms would provide consistency in physical properties over a range of environments common to manufacturing and composition usage. Thus, there is a need for new drug forms that are useful for inhibiting E1 activity in vitro and in vivo, and are useful for the treatment of disorders of cell proliferation, particularly cancer, and other disorders associated with E1 activity, as well as having properties suitable for large-scale manufacturing and formulation.